WO2021254558A1

WO2021254558A1 - Crankshaft assembly with a centrifugal pendulum attached to the crankshaft

Info

Publication number: WO2021254558A1
Application number: PCT/DE2021/100439
Authority: WO
Inventors: Mathias Girnus; Pascal Strasser
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2020-06-17
Filing date: 2021-05-18
Publication date: 2021-12-23
Also published as: US20230213085A1; DE102020115930A1; CN115516228A; DE102020115930B4

Abstract

The invention relates to a crankshaft assembly (1) for a motor vehicle drive train, comprising a crankshaft segment (2) and a centrifugal pendulum (3) secured thereon, which has a carrier (4) secured to the crankshaft segment and at least one pendulum mass (5) that moves relative to the carrier (4) along a predetermined track, wherein the crankshaft assembly (1) has a friction unit (7) connected to the carrier (4), which rests on the at least one pendulum mass (5) such that, with a relative movement of the pendulum mass (5) in relation to the carrier (4), the friction unit (7) applies a frictional torque on the pendulum mass (5) counteracting the relative movement, wherein the friction unit (7) extends over a peripheral section of less than 360°.

Description

Crankshaft arrangement with centrifugal pendulum attached to the crankshaft

The invention relates to a crankshaft assembly for a motor vehicle drive train. The crankshaft assembly has a crankshaft segment and a centrifugal pendulum attached to it. The centrifugal pendulum has a crankshaft segment fixed carrier and at least one pendulum mass movable relative to the carrier along a vorbe certain career.

From the prior art it is already known to attach a centrifugal pendulum to a cure belwelle to absorb natural frequency vibrations of the crankshaft. For example, DE 102016 121 397 A1 and DE 102017 120426 A1 each disclose a pendulum arrangement which is attached ra dial to an outer peripheral surface of the crankshaft.

However, the prior art always has the disadvantage that the provision of a centrifugal pendulum requires additional installation space and increases the total weight of the crankshaft and that a connection of the centrifugal pendulum to the crankshaft can weaken the crankshaft.

It is therefore the object of the invention to avoid or at least mitigate the disadvantages of the prior art. In particular, a crankshaft arrangement is to be provided in which a centrifugal pendulum pendulum can be designed to be space-efficient and weight-efficient and attached to the crankshaft without any negative effects on functionality, strength, manufacturability and / or costs.

This object is achieved by a crankshaft assembly having the features of tentanspruchs 1 Pa. Advantageous further developments are claimed in the subclaims.

Accordingly, the crankshaft arrangement has a crankshaft segment, that is to say an in particular an axial section of a crankshaft, and a, in particular direct, segment the centrifugal pendulum attached to the crankshaft segment. The centrifugal pendulum is used to absorb the natural frequency oscillation of the crankshaft. Torsional vibrations / rotations of the crankshaft can therefore be eliminated by the centrifugal pendulum. The centrifugal pendulum is preferably tuned to higher oscillation orders, for example to oscillation orders greater than a first order, preferably greater than a second order. For example, the centrifugal pendulum can be tuned to a third order, a fourth order, a four and a half order, a sixth order or the like.

The centrifugal pendulum has a support fixed to the crankshaft segment and at least one pendulum mass which is movable relative to the support along a predetermined track. To meet the resonance condition to compensate for torsional vibrations, the raceway preferably has components in the circumferential direction and in the radial direction.

In particular, the crankshaft segment can have an eccentric mass area (relative to the axis of rotation of the crankshaft / the crankshaft segment) through which an imbalance occurs / is forced during operation / rotation of the crankshaft arrangement. The mass area is formed, for example, by a connecting rod bearing area of the crankshaft segment.

The crankshaft arrangement has a friction device, in particular non-rotatably connected to the carrier, which rests against the at least one pendulum mass in such a way that the friction device applies a friction torque to the pendulum mass that counteracts the relative movement when the pendulum mass moves relative to the carrier. This has the advantage that the additional friction that acts on the relative movement / oscillating movement of the centrifugal pendulum, in particular the pendulum mass, improves isolation of the natural frequency oscillation of the crankshaft and the required oscillation angle can be reduced. In this way, the functional parameters such as mass, oscillation angle and friction can be made available to the required extent. The friction device extends over a circumferential section of less than 360 °. This means that the friction device is not designed to be completely circumferential in the circumferential direction. A circumferential direction is defined in particular in relation to an axis of rotation of the crankshaft segment. This has the advantage that the friction device can only be formed in that area in which it is needed. In addition, a non-circumferential friction device has an advantageous effect on compensating for an imbalance caused by the crankshaft segment. The circumferential section can preferably be between 90 ° and 270 °, in particular between 180 ° and 270 °.

According to a preferred embodiment, the at least one pendulum mass extends over a predetermined circumferential section. The circumferential section over which the friction device extends can correspond in particular to the predetermined circumferential section. Thus, a normal force / axial force and a friction element system are provided by the friction device only in the area of the pendulum mass (s). In addition, this has the advantage that the friction device does not require any additional contact surface in an area in which the pendulum mass (s) are not formed.

According to an advantageous development, the friction device can be segmented, in particular in a substantially circular (ring) sector-shaped manner. Such a shape has proven to be particularly advantageous for the application in a crankshaft segment.

According to the preferred embodiment, the friction device can have a friction element resting against the pendulum mass, a receiving disc connected in a rotationally fixed manner to the carrier and a spring element supported / braced axially between the friction element and the receiving disc. Through the spring element, a normal force / axial force is applied to the friction element, which presses the Reibele element axially against the pendulum mass.

The receiving disk can preferably over a circumferential section of less than 360 °, for example between 90 ° and 270 °, in particular between 180 ° and 270 °, be formed. Alternatively or additionally, the friction element can preferably be formed over a circumferential section of less than 360 °, for example between 90 ° and 270 °, in particular between 180 ° and 270 °. Alternatively or additionally, the spring element can preferably be formed over a circumferential section of less than 360 °, for example between 90 ° and 270 °, in particular between 180 ° and 270 °.

According to the preferred embodiment, the friction device can additionally have a cover disk arranged axially between the spring element and the friction element. By providing the cover disk, a contact area between the spring element and the friction element, i.e. with respect to the friction element, can be enlarged so that a permissible surface pressure of the friction element is not exceeded.

The cover disk can preferably be formed over a circumferential section of less than 360 °, for example between 90 ° and 270 °, in particular between 180 ° and 270 °.

According to a preferred embodiment, the friction device can be arranged in the circumferential direction essentially opposite the mass region of the crankshaft segment that generates the unbalance, in particular arranged eccentrically with respect to the axis of rotation. This has the advantage that eliminating the mass of the friction device in the mass area can help to compensate for the imbalance.

According to a preferred embodiment, the friction device can be designed to be axially symmetrical. In particular, an axis of symmetry of the friction device can correspond to an axis of symmetry of the mass area which, for example, orthogonally intersects the axis of rotation. Such a configuration has a particularly advantageous effect on concentricity / unbalance compensation of the crankshaft segment. According to a particularly preferred embodiment, the centrifugal pendulum can be dimensioned with respect to the mass and the position on the crankshaft segment selected so that the centrifugal pendulum has an imbalance compensating effect on the crankshaft segment during operation, ie when the crankshaft segment rotates. The friction device can be viewed as part of the centrifugal pendulum. This means that the centrifugal pendulum and / or the friction device as such forms an unbalance compensation mass for the crankshaft / crankshaft segment. Thus, the centrifugal pendulum replaces an unbalanced mass (which has to be provided otherwise, ie if no centrifugal pendulum is present). It can therefore be said that an imbalance occurring during rotation of the crankshaft segment is predominantly or completely compensated for by the choice of the mass of the centrifugal pendulum and a mounting location of the centrifugal pendulum on the crankshaft segment.

This has the advantage that the centrifugal pendulum not only fulfills the actual Til supply function, but also acts as an unbalance compensation. As a result of this double function of the centrifugal pendulum, the total mass / total weight of the crankshaft arrangement (or the crankshaft) does not increase as a result of the provision of the centrifugal pendulum. Since the centrifugal pendulum replaces an unbalanced mass, the individual mass / the individual weight of the crankshaft segment is reduced by the unbalanced mass replaced / omitted due to material removal, which in turn corresponds to the individual mass / the individual weight of the added centrifugal pendulum. Simply put, the weight of the crankshaft remains the same with and without a centrifugal pendulum. In other words, an unbalanced mass of the crankshaft has an additional centrifugal force pendulum function.

According to a preferred embodiment, the crankshaft segment can have an end face recess for receiving at least part of the centrifugal pendulum. The recess can in particular be dimensioned / have such a dimension that the recess has an unbalance-compensating effect when the crankshaft segment rotates. This means that in particular so much material / mass has been removed for the recess that it is compensated for again by the provision of the additional components, namely the centrifugal pendulum. The exceptional tion can be provided subsequently by machining or already in the raw part on the crankshaft segment. As a result, manufacturing costs can be saved.

According to the preferred embodiment, the volume of the recess can be compensated at least partially by the volume of the centrifugal pendulum (and / or the Reibein direction). In other words, the recess is arranged in such a way that the volume can be used for arranging the components such as the centrifugal pendulum.

In particular, the recess can be arranged in the axial direction essentially at the same height as the mass area of the crankshaft segment. The recess can also be arranged essentially opposite the mass area in the circumferential direction. Furthermore, it can be expedient to arrange the recess essentially radially at the same distance from the axis of rotation as the mass area, for example a center of gravity of the mass area, is away from the axis of rotation (in the other direction).

According to an advantageous embodiment, the centrifugal pendulum can have several pendulum masses. In particular, according to the advantageous embodiment, the pendulum masses can be arranged asymmetrically in the circumferential direction. The unbalance properties of the crankshaft arrangement can be favorably influenced by the uneven distribution over the circumference.

Alternatively or additionally, the pendulum masses according to a preferred embodiment, in particular a resulting center of gravity of the pendulum mass (s), can be arranged essentially opposite the mass area of the crankshaft segment in the circumferential direction.

According to a preferred embodiment, a centering area for centered accommodation of the centrifugal pendulum can be formed on a radial outer circumference of the crankshaft segment. The centering area can subsequently be machined or are already provided in the raw part on the crankshaft segment. As a result, manufacturing costs can be saved.

According to a preferred embodiment, a screw-on surface to which the centrifugal pendulum is attached can be formed on an axial end face of the crankshaft segment. Due to the axial fastening, a required oscillation angle of the centrifugal pendulum can be realized in a particularly simple manner. The screw-on surface can subsequently be machined or provided in the raw part on the crankshaft segment. As a result, manufacturing costs can be saved. Preferably, in the area of the screw-on surface, threaded bores can be provided in the crank shaft segment, so that the centrifugal pendulum (the carrier) can simply be screwed in.

It is particularly preferred if the screw-on surface is arranged radially outside a connection area of the crankshaft segment, the connection area being designed to connect a second, adjacent crankshaft segment to the crankshaft segment. This ensures that the crankshaft segment is not impermissibly weakened in its stress-critical area by the attachment of the centrifugal pendulum. For example, the screw surface can be arranged essentially opposite the mass area of the crankshaft segment in the circumferential direction.

It is further preferred if the friction device and the centrifugal pendulum are attached to the crankshaft segment, for example on the screw surface, via a common fastening device. This has the advantage that, for example, the number of threaded bores can be reduced so that the crankshaft segment is weakened as little as possible.

In one embodiment, the friction device can be designed to run around in the circumferential direction. For example, the friction element can have the shape of a circular ring in cross section, ie it can be designed as a friction ring. A rotationally symmetrical metric design of the friction element, this can be manufactured particularly inexpensively and easily installed.

The receiving disk can, for example, be designed as a potted sheet metal component. For example, the receiving disk is produced without cutting, for example as a formed component, in particular a deep-drawn component. The receiving disk can preferably have two radial sections connected to one another via an axial section, so that a substantially S-shape results in a longitudinal section. A first (inner) radial section can serve as a fastening section for attachment to the crankshaft segment. A second (outer) radial section can serve as a support section for axially supporting the spring element and / or the friction element. The receiving disc can be folded over at its radially outer end, i.e. have an axial projection on which the friction element rests in the circumferential direction.

The spring element can be designed as a plate spring or a wave spring. In particular, the spring element can be attached to the receiving disk in a rotationally fixed manner. For example, the spring element can be rotatably attached to the receiving disc by a rivet connection.

According to a preferred embodiment, the crankshaft arrangement can have a burst protection (catcher basket) which is fixed to the crankshaft segment and which surrounds the centrifugal pendulum radially on the outside in such a way that when the centrifugal pendulum rotates, components of the centrifugal pendulum loosening are caught and / or braked by the burst protection. In other words, the centrifugal pendulum is potted up by the burst protection so that it is encompassed / enclosed radially on the outside. This has the advantage that components loosening due to the rotation cannot be thrown outwards in an uncontrolled manner. The burst protection accordingly forms a barrier for components flying outwards due to the centrifugal force, whereby damage to their components of the motor vehicle drive train can be prevented.

According to a preferred embodiment, the burst protection can cut a Radialab, which is located on a first (crankshaft segment facing away) axial side of the Centrifugal pendulum extends radially outward, and an outer axial section be seated, which extends radially outside of the centrifugal pendulum from the radial section, in particular from a radially outer end of the radial section, in the axial direction to a second (crankshaft segment facing) axial side of the centrifugal pendulum. In other words, the burst protection extends on a radial outside of the centrifugal pendulum in the direction of the crankshaft segment. In particular, the outer axial section extends at least so far that the pendulum mass (s) are completely covered in the axial direction. In particular, the radial section is extended radially outward so far that it extends radially outward beyond the centrifugal pendulum (the pendulum mass). The outer axial section and the radial section are connected, for example, via a crank / curvature.

According to the preferred embodiment, the outer axial section can extend over a circumferential section of less than 360 °, preferably between 90 ° and 270 °. In other words, the outer axial section has a circular arc-shaped cross section. In particular, the outer axial section extends only over that circumferential section in which the pendulum mass (s) is / are arranged. This has the advantage that the burst protection is only formed where it has to fulfill its function, so that material and thus weight can be saved. In particular, the installation space required for the crankshaft segment is not restricted by the burst protection.

According to the preferred embodiment, the friction device, in particular the receiving disk, can form the burst protection. This means that a component, in particular the receiving disk, is extended in such a way that it encompasses the centrifugal pendulum radially on the outside and can serve as a protection against bursting. This has the advantage that no additional component has to be provided to form the burst protection. The recording mescheibe can be extended due to its structure particularly suitable without affecting other functions of the receiving disk or the centrifugal pendulum. The receiving disk can preferably be designed as a potted sheet metal component. A sheet metal component can be brought into a desired pot-like shape in a particularly simple manner. Under potted is understood in particular that the receiving disc has the radial section and the outer axial section as well as an inner Axialab section which extends from a radially inner end of the radial section in the axial direction, in particular in the direction of the second axial side of the centrifugal pendulum. Thus, the radial section and the two axial sections form a U-shape in longitudinal section, within which the pendulum mass (s) of the centrifugal pendulum is / are arranged (so that the pendulum mass (s) are encompassed). The top-quality cranking of the mounting washer improves the stability of the mounting washer.

In particular, the receiving disk can be formed without cutting, for example as a formed component, preferably as a deep-drawn component. In this way, the geometry, in particular the U-shape and / or the S-shape, can be easily produced.

According to a preferred embodiment, the friction element can be received on its radial outer side in a rotationally fixed manner in the receiving disk, in particular the axial section of the burst protection / receiving disk. As a result, the friction element can be arranged radially further outwards, so that the friction surface is advantageously enlarged.

According to the preferred embodiment, the friction element can have radially outwardly protruding projections which engage in corresponding recesses in the receiving disk to prevent rotation. In other words, the rotation lock is implemented through recesses in the receiving disk and penetrations in the friction element. In this way, the friction element can be attached to the receiving disk in a form-fitting and rotationally fixed manner in a manner that is easy to manufacture.

According to the preferred embodiment, the receiving disk can alternatively (or additionally) have radially inwardly protruding deformation areas, for example in the manner of an arc spring stop in a dual-mass flywheel, which lock into corresponding pockets of the friction element. In this way, the friction element can be attached to the receiving disk in a form-fitting and rotationally fixed manner in a manner that is easy to manufacture.

According to a preferred embodiment, the friction element can bear axially on the Ra dial section of the receiving disk. Tilting of the friction element is advantageously prevented by the two-sided planar support of the friction element.

According to a preferred embodiment, the carrier of the centrifugal pendulum can be extended on a side opposite the pendulum mass in the circumferential direction in such a way that the friction device rests against the carrier. This means that the carrier forms an abutment for the friction device on the side opposite the pendulum mass in the circumferential direction. This has the advantage that even with an asymmetrical arrangement of the pendulum mass (s) over the circumference in the angular range within which the friction device has no abutment by the pendulum mass (s), one-sided loading and inclination of the friction device is avoided or it can be counteracted. In other words, the missing abutment is compensated for by the special geometry of the support of the centrifugal pendulum. Thus, part of the carrier for receiving the pendulum mass (s) is seen and the remaining part is designed so that it provides a contact surface for the Reibein direction.

In particular, the friction element of the friction device can rest against the carrier (or be supported on it). This means that the friction element rests against the pendulum mass (s) in a first circumferential area and rests against the carrier in another, in particular essentially opposite, second circumferential area. One-sided loading of the friction element is thus avoided.

The friction device can preferably rest on the same axial side on the at least one pendulum mass and on the carrier. This has the advantage that the normal force applied by the spring element can be supported evenly and / or over a (large) area. According to an advantageous development, the carrier can have a bearing section extending in the radial direction for receiving the at least one pendulum mass and a bearing section extending in the radial direction for supporting the friction device. Preferably, the bearing section and the Anlageab section are arranged parallel to one another and spaced apart in the axial direction. As a result, a flat contact surface for the friction device can be provided in an advantageous manner and at the same time the support of the pendulum mass on the carrier can be guaranteed.

According to the advantageous development, an axial distance between the bearing section and the contact section can essentially correspond to the thickness of the at least one pendulum mass. This has the advantage that a flat friction element can rest axially flush against the pendulum mass and against the contact section or can be supported thereon.

According to the embodiment, the bearing section and the contact section can be connected by a connecting section of the carrier, so that the carrier has an essentially S-shape in longitudinal section. As a result, sufficient de rigidity and strength of the carrier can be guaranteed.

In addition, it has proven to be advantageous if the contact section is formed by potting the carrier in the direction of the friction device. In this way, the required shape of the carrier can be produced with little effort.

It is also useful if the carrier is designed as a formed sheet metal part. For example, the carrier can be produced without cutting. In particular, the carrier can be produced by stamping and reshaping, for example by deep drawing. In this way, the carrier can be manufactured inexpensively and in large numbers. The contact section can preferably have the shape of a Kreisringbo gene in cross section. This has the advantage that the contact section provides a suitable contact surface for a simple form of the friction element.

In other words, the invention relates to a crankshaft arrangement in which a centrifugal pendulum subassembly is arranged on an unbalance compensation cheek of a crank shaft segment. On the crankshaft segment there is a receptacle for the FKP UZSB, which is machined or designed in the raw part in such a way that a centering seat, a screw-on surface and an area in which the pendulum mass (s) can swing is provided A centrifugal pendulum carrier (flange) is arranged which is screwed into threaded bores in the crankshaft segment in the non-stress-critical area. By means of a Reibein direction, additional friction, which acts on the centrifugal pendulum oscillation movement, is provided, which improves the isolation of the natural frequency oscillation of the crankshaft and reduces the required oscillation angle. The friction device has a potted receiving disc. A plate spring is supported on the one hand on the receiving disk and on the other hand a normal force acts on a friction element, which in turn rests on the pendulum mass. If necessary, a cover plate can also be provided between the plate spring and the friction element so that the permissible surface pressure of the friction element is not exceeded. The friction element is rotatably leads out with the receiving disk, so that the friction point between the friction element and the pendulum mass is Festge. The pendulum masses are arranged asymmetrically on the circumference, so that they serve to compensate for the unbalance of the crankshaft. In particular, the friction device can not be designed circumferentially, but only as a ring segment, whereby a normal force and friction ring system is provided in the required area of the pendulum mass and there is no exposed area of the friction device that needs to be supported. So If the mass of the friction device is omitted in the area that is not required, an imbalance due to the mass of the crankshaft segment that is removed for the centrifugal pendulum can also be compensated for. Both a receiving disk, a spring element, a Rei element and a cover disk can be segmented / not circumferential, but only exist in the area of the pendulum masses. Alternatively or in addition, a burst protection can preferably be integrated into the receiving disk (supporting disk / receiving plate), for which purpose the receiving plate is extended radially outward and potted over the centrifugal pendulum. A rotation lock between the receiving plate and the friction element (friction ring) can be implemented by means of recesses in the receiving plate and penetrations in the friction element or alternatively by means of reshaped areas in the receiving plate, which engage in corresponding pockets in the friction element. Furthermore, particularly in the case of an arrangement of the pendulum masses that is not symmetrical in the circumferential direction, the carrier of the centrifugal pendulum can be designed in such a way that it forms an abutment for the friction device. Thus, only part of the carrier is provided for receiving the pendulum masses and the remaining area is designed in such a way that a contact surface is provided for the friction device. More preferably, this contact surface can be formed by an annular region which is potted in the direction of the friction device.

The invention is explained below with the aid of drawings. Show it:

Figs. 1 and 2 show a longitudinal sectional view and a plan view of a crankshaft arrangement in a first embodiment,

Figs. 3 and 4 a longitudinal sectional view and a plan view of a crankshaft arrangement in a second embodiment,

Figs. 5 and 6 show a longitudinal sectional view and a plan view of a crankshaft arrangement in a third embodiment, and

Figs. 7 to 9 show a longitudinal sectional illustration and perspective views of a crankshaft arrangement in a fourth embodiment. The figures are only of a schematic nature and are used exclusively for understanding the invention. The same elements are provided with the same reference symbols. The features of the individual embodiments can be interchanged with one another.

Figs. 1 to 9 show different embodiments of a crankshaft arrangement 1 for a motor vehicle drive train. The crankshaft assembly 1 has a cure belwellensegment 2. The crankshaft segment 2 is a particular axial part piece of a crankshaft. The crankshaft arrangement 1 has a centrifugal pendulum 3 fastened to the crankshaft segment. The centrifugal pendulum 3 serves to absorb a natural frequency oscillation of the crankshaft or a flake exciter order of the motor vehicle drive train.

The centrifugal pendulum 3 has a carrier 4 fixed to the crankshaft segment. The Trä ger 4 is therefore attached to the crankshaft segment 2 in a rotationally fixed manner. The centrifugal pendulum 3 has at least one pendulum mass 5. The pendulum mass 5 is attached to the carrier 4 so as to be movable relative to the carrier 4 along a predetermined track. Due to the relative movement between the pendulum mass 5 and the Trä ger 4, the damper effect of the centrifugal pendulum 3 is achieved. In the illustrated embodiments, the centrifugal pendulum 3 has a plurality of pendulum masses 5, which are arranged asymmetrically in order circumferential direction / over the circumference. The circumferential direction is defined in relation to an axis of rotation of the crankshaft segment 2.

The centrifugal pendulum 3 is dimensioned with regard to its mass and is arranged with regard to its position on the crankshaft segment 2 so that the centrifugal pendulum 3 acts on the crankshaft segment 2 during operation, ie when the crankshaft segment 2 rotates. The crankshaft segment 2 has a mass region 6 which generates an imbalance during operation. The mass area 6 is arranged eccentrically to the axis of rotation. The mass and the position of the centrifugal pendulum 3 is therefore matched to the mass and the position of the mass area 6 from. The centrifugal pendulum 3 (in particular its pendulum masses 5) are in Arranged in the catch direction opposite to the mass area 6. The centrifugal pendulum 3 is arranged in the axial direction (in relation to the axis of rotation) at the same height as the mass area 6. The pendulum masses 5 are at the same radial distance from the axis of rotation as the mass area 6. In other words, the centrifugal pendulum 3 serves as an unbalance compensation element for the mass area 6.

This means that the centrifugal pendulum 3 replaces an unbalanced mass for the crankshaft segment 2 (partially or completely).

The crankshaft arrangement 1 has a friction device 7 connected to the carrier 4. The friction device 7 is non-rotatably attached to the carrier 4 and / or to the cure belwellensegment 2. The friction device 7 rests against the at least one pendulum mass 5 in such a way that the friction device 7 applies a friction torque to the pendulum mass 5 that counteracts the relative movement when the pendulum mass 5 moves relative to the carrier 4. The friction device 7 has a friction element 8 resting on the pendulum mass 5. The friction device 7 has a receiving disk 9 which is connected to the carrier 4 in a rotationally fixed manner. The friction element 8 is connected to the receiving disk 9 in a rotationally fixed manner. The friction device 7 has an axi al between the friction element 8 and the receiving disk 9 supporting, in particular tensioned, spring element 10. The spring element 10 is designed, for example, as a plate spring or a corrugated spring. A normal force / axial force is applied to the friction element 8 by the spring element 10, which presses the friction element 8 axially against the pendulum mass 5, so that a friction torque which counteracts the relative movement arises during a relative movement between the friction element 8 and the at least one pendulum mass 5 .

The crankshaft segment 2 has an unbalance compensation beam 11. The Un balancing cheek 11 lies opposite the mass area 6 in the circumferential direction. The crankshaft segment 2 has an end-face recess 12 (in the Unwuchtaus equal cheek 11) for receiving at least part of the centrifugal pendulum 3, in particular the pendulum masses 5. The recess 12 is dimensioned such that it has an imbalance-compensating effect when the crankshaft segment 2 rotates. In particular, the mass removed for the recess 12 corresponds to a mass added by the centrifugal pendulum 3. The crankshaft segment 2 has a connection region 13 which is designed to fasten an (axially adjacent) second crankshaft segment to it. The connection area 13 is arranged centrally on the crankshaft segment 2. The recess 12 is arranged radially outside of the connection area 13. The crankshaft segment 13 has on its radial outer circumference a Zentrierbe rich 14 for centered reception of the centrifugal pendulum 3. The crankshaft segment 13 has on an axial end face a screwing area / a screwing surface 15 to which the centrifugal pendulum 3 / the carrier 4 is attached. The screw-on surface 15 is arranged radially outside of the connection area 13. The centrifugal pendulum 3 is attached axially to the screw-on surface 15 via a fastening device 16, in particular in the form of several screws. For this purpose, threaded bores into which the fastening device 16 is screwed are provided in the screw-on surface 15.

The receiving disk 9 of the friction device 7 is formed as a potted sheet metal component. The receiving disk 9 has an (inner) first radial section 17 which serves as a fastening section. The radial section 17 is fixedly attached to the carrier 4 and the crankshaft segment 2 via the fastening device. From a radially outer end of the first radial section 17, an axial section 18 extends away from the crankshaft segment 2 / the screw-on surface 15 in the axial direction. The axial section 18 extends radially inside the pendulum masses 5.

From an axially remote end of the axial section 18, an (outer) second radial section 19 extends outward in the radial direction. As a result, the receiving disk 9 has at least some sections of an S-shape. The spring element 10 and / or the friction element 8 are supported axially on the receiving disk 9 in the region of the second radial section 19. From a radially outer end of the second Ra dial section 19, an axial projection 20 extends in the axial direction towards the pendulum masses 5. The spring element 10 and / or the friction element 8 are supported in the circumferential direction on the axial projection 20.

The centrifugal pendulum 3 has in the illustrated embodiment several pendulum mass packages. Each pendulum mass package has two pendulum masses 5, the are held axially parallel spaced by one or more spacer elements 21. The two pendulum masses 5 are connected to one another via a rivet 22, for example.

Figs. 1 and 2 show a first embodiment of the crankshaft arrangement 1. In FIG. 1, a plan view without showing the friction device 7 is shown. The Trä ger 4 has a central through hole 23 through which the carrier 4 is centered on the centering area 14. In the first embodiment, the friction element 8 is designed as a friction ring rotating in the circumferential direction. The friction element 8 has form-locking elements 24 on its radially inner side, which engage corresponding recesses 25 in the receiving disk 9 in order to secure against rotation in a form-locking manner. The friction element 8 is thus fastened radially on the inside. The receiving disk 9 is designed to run around in the circumferential direction. The second radial section 19 and / or the axial projection 20 are / is rotationally symmetrical.

Figs. 3 and 4 show a second embodiment of the crankshaft arrangement 1. Only differences from the first embodiment are explained below. The friction device 7 has an additional cover disk 26 which is arranged in the axial direction between the spring element 10 and the friction element 8. The crankshaft assembly 1 has a burst protection 27. The burst protection 27 surrounds the centrifugal pendulum 3 radially on the outside. As a result, 3 loosening components are caught by the burst protection 27 during rotation of the Fliehkraftpen dels. The burst protection 27 is formed by the receiving disk 9. The second radial section 19 is extended radially outward so that it protrudes radially outward beyond the pendulum masses 5. From a radially outer end of the second radial section 19, an outer axial section 28 extends in the axial direction towards the crankshaft segment 2. The outer axial section 28 extends axially beyond the pendulum masses 5. This means that the axial projection 20 is extended in the axial direction, at least in the circumferential area of the pendulum masses 5, in order to form the outer axial section 28. The pendulum masses 5 are accordingly potted by the receiving disk 9. On the receiving disk 9 has to form the burst protection 27 on a U-shape, which engages around the pendulum masses 5 potted axially. The friction element 8 is fastened radially on the outside on the receiving disk 9 to prevent rotation. For example, the travel belement 8 and the receiving disk 9 into one another. The friction element 8 is supported in a radially inner region on the cover disk 26 and in a radially outer region on the receiving disk 9. The carrier 4 extends approximately in the shape of a crescent in the area of the pendulum masses 5.

Figs. 5 and 6 show a third embodiment of the crankshaft arrangement 1. Only differences from the first or second embodiment are explained below. In the third embodiment, the friction device 7, in particular the receiving disk 9, the friction element 8, the spring element 10 and / or the cover disk 26, extends over a circumferential section of less than 360 °. This means that the friction device 7 is not completely circumferential in the circumferential direction. The circumferential section is between 90 ° and 270 °, in particular between 180 ° and 270 °. The circumferential section essentially corresponds to a predetermined circumferential section over which the pendulum masses 5 extend. The Reibeinrich device 7 is segmented, in the embodiment shown, circular (ring) sector-shaped. The friction device 7 can be viewed as part of the centrifugal pendulum 3, so that the design, dimensioning and positioning of the friction device 7 also has an imbalance-compensating effect on the crankshaft segment 2 during operation.

Figs. 7 to 9 show a fourth embodiment of the crankshaft arrangement 1. Only differences from the first, second or third embodiment are explained below. In the fourth embodiment, the carrier 4 of the centrifugal pendulum 3 is extended on a side opposite the pendulum masses 5 in the circumferential direction in such a way that the friction device 7 rests against the carrier 4. The carrier 4 thus extends in the radial direction and circumferential direction as far as the mass area 6. The carrier 4 has a connecting section in the form of an axial pot 29, which connects a first radial section 30 adjacent to the pendulum masses 5 in the circumferential direction with a second radial section 31 adjacent to the mass area 6 in the circumferential direction. The second radial section 31 is potted in the direction of the friction device 7. The first radial section 30 is arranged axially parallel to the second radial section 31. The first radial section 30 serves as a bearing section for receiving the pendulum masses 5. The second radial Dial section 31 serves as a contact section against which the friction device 7 rests. In particular, the friction element 8 rests on the same axial side in a circumferential section on the second radial section 31 and in another circumferential section on the pendulum masses 5. The carrier 4 has a through hole 32. The through hole 32 is formed eccentrically. In an area adjacent to the pendulum masses 5 in the circumferential direction, a radial inner side / inner surface of the carrier 4 rests on the centering area 14. The through hole 32 extends radially further outward in an area adjacent to the mass area 6 in the circumferential direction, so that the carrier 4 rests on the crankshaft segment 2 only over a circumferential section which is smaller than 360 °.

Bezuqszeichenliste crankshaft arrangement crankshaft segment centrifugal pendulum carrier pendulum mass mass area friction device friction element receiving disk spring element unbalance compensation cheek recess connection area centering area screwing surface fastening device first radial section axial section second radial section axial projection spacer element rivet through hole form-fitting element recess cover disk burst protection Axial section pot first radial section second radial section through hole

Claims

1. Crankshaft arrangement (1) for a motor vehicle drive train, with a crankshaft segment (2) and a centrifugal pendulum (3) attached to it, which has a carrier (4) fixed to the crankshaft segment and at least one pendulum mass (5) which is movable relative to the carrier (4) along a predetermined track ), characterized in that the crankshaft arrangement (1) has a friction device (7) connected to the carrier (4), which rests against the at least one pendulum mass (5) in such a way that the friction device (7) during relative movement of the pendulum mass (5) applies to the carrier (4) a friction torque counteracting the relative movement on the pendulum mass (5), the friction device (7) extending over a circumferential section of less than 360 °.

2. Crankshaft arrangement (1) according to claim 1, characterized in that the circumferential section is between 90 ° and 270 °.

3. Crankshaft arrangement (1) according to claim 1 or 2, characterized in that the at least one pendulum mass (5) extends over a predetermined circumferential section, the circumferential section over which the friction device (7) extends corresponds to the predetermined circumferential section.

4. Crankshaft arrangement (1) according to one of claims 1 to 3, characterized in that the friction device (7) is segmented.

5. The crankshaft arrangement (1) according to one of claims 1 to 4, characterized in that the friction device (7) has a friction element (8) attached to the pendulum mass (5), a receiving disk connected to the carrier (4) (9) and a spring element (10) supported axially between the friction element (8) and the receiving disk (9), the receiving disc (9), the friction element (8) and / or the spring element (10) are formed over a circumferential section of less than 360 °.

6. Crankshaft arrangement (1) according to one of claims 1 to 5, characterized in that the friction device (7) is arranged in the circumferential direction essentially opposite to an imbalance-generating mass region (6) of the crankshaft segment (2).

7. Crankshaft arrangement (1) according to claim 6, characterized in that the friction device (7) is formed axially symmetrically, with a symmetry axis of the friction device (7) corresponds to an axis of symmetry of the mass area (6).

8. Crankshaft arrangement (1) according to one of claims 1 to 7, characterized in that the centrifugal pendulum (3) and / or the friction device (7) are / is so dimensioned with respect to the mass and the position on the crank shaft segment (2) so it is selected that the centrifugal pendulum (3) and / or the friction device (7) acts in a compensating manner on the crankshaft segment (2) when the crankshaft segment (2) rotates.

9. Crankshaft arrangement (1) according to claim 8, characterized in that the crankshaft segment (2) has an end-face recess (12) for receiving at least part of the centrifugal pendulum (3) and / or the friction device (7), the recess (12) ) is dimensioned so that it has an imbalance compensation effect when the crankshaft segment (2) rotates.

10. Crankshaft assembly (1) according to claim 8 or 9, characterized in that on an axial end face of the crankshaft segment (2) a screw surface (15) is formed on which the friction device (7) and the centrifugal pendulum (3) via a common Fastening device (16) are attached.